The best picture I have is this one from around 1935, which shows Carl's Place Bar & Club, which became the Main Entrance Casino three years later. It is down the alley between Beecher's Nevada Club on the right and Carl Tychsen's Stateline Market on the left. In the background to the far left is the Stateline Country Club. Tychsen owned this property until his death in 1945, so it was never part of the Stateline Country Club during the time the Main Entrance Casino was open.

In this photo, from around 1939, you can see the round Main Entrance Casino canopy extending out of the alley between the Stateline Market and the Nevada Club, still separate from the Stateline Country Club:

In this last photo from the early 1940s, it looks like the Stateline Market has closed and the Main Entrance Casino has taken over the whole place (but the property is still owned by Carl Tychsen, according to Douglas County deed books):

My point is that at no time did the same people own the Stateline Country Club and the Main Entrance Casino properties. In the late '40s, the Sahati family would own both, but that's after the Main Entrance Casino closed and was renamed the Itahas Lodge (Sahati spelled backwards).